松湖铁矿深部矿体无底柱分段崩落法放矿参数优化研究

一般而言,制约无底柱分段崩落法回采指标优劣的关键参数包括放矿方式、分段高度、进路间距与崩矿步距等。随着国内外相关采矿设备的发展,上述放矿参数也在逐步增大。以松湖铁矿无底柱分段崩落法采矿为例,在分析现有放矿参数存在的问题后,提出了从放矿方式、进路间距、放矿步距(崩矿步距)三个方面优化确定合理的放矿参数。借助Image Pro Plus图像处理软件,对井下出矿进路爆堆及地表摊平矿堆进行拍照分析,确定了松湖铁矿崩落法采场实际矿岩块度粒级。根据相似物理模型试验要求,相似比选择为1∶100,通过对比5 mm以下原矿与10 mm以下原矿、5 mm以下原矿与6 mm以下配矿的椭球体形态参数,确定了采用6 mm以下配矿散体用来模拟原矿全粒级的放矿椭球体形态。在上述基础上,通过开展单口放矿试验与多口放矿试验,以回贫差作为评判指标,推荐松湖铁矿采用无贫化放矿方式组织生产作业,确定了最佳进路间距宜采用13.5 m,并且综合确定了最优崩矿步距为4 m。采用上述放矿参数之后,贫化率由现在的21.35%降低至8.77%,损失率由现在的23.61%降低至13.4%,改善了崩落法采矿的回采指标,为松湖铁矿深部矿体回采参数设计提供了技术支撑。

Optimization of Drawing Parameters of Sublevel Caving Method for Deep Orebody in Songhu Iron Mine

Generally speaking, the key parameters of the stoping index of sublevel caving include drawing method, sublevel height, access span and drawing loop distance. With the development of relevant mining equipment at home and abroad, the above ore drawing parameters are gradually increasing. Taking sublevel caving in Songhu Iron Mine as an example, the problems in the existing drawing parameters are analyzed in the paper, and the optimization solution of the reasonable drawing parameters from three aspects of drawing method, access span and drawing loop distance (or caving loop distance) is put forward. Using Image Pro Plus image processing software, the actual ore and rock size of Songhu Iron Mine caving stope is determined by photographing and analyzing the blasting pile in the access. According to the requirement of similar physical model test, the similar ratio is selected as 1:100. By comparing the ellipsoid shape parameters of the actual ore with less than 5mm and less than 10mm, actual ore with less than 5mm and processed ore with less than 6mm, it is determined that the processed ore with less than 6mm is used to simulate the actual ore drawing ellipsoid shape. On the basis of the above, it is recommended that Songhu Iron Mine should organize production operation by non-dilution ore drawing method through single drawing test and multiple drawing test, and it is determined that the optimal access span should be 13.5m, and the optimal caving loop distance is comprehensively determined to be 4m. After the above drawing parameters are adopted, the dilution rate is reduced from the current 21.35% to 8.77% and the loss rate is reduced from the current 23.61% to 13.4%, which improves the stoping index of sublevel caving and provides technical support for the design of stoping parameters of deep orebody in Songhu iron mine.